Abstract: A system and a method for heating source fluid, comprising: a turbine-electric generator transport comprising: an inlet plenum and an exhaust collector; a turbine connected to the inlet plenum and the exhaust collector; and an electric-generator coupled to the turbine; an exhaust heat recovery transport comprising: a combustion air connection coupled to the inlet plenum; an exhaust air connection coupled to the exhaust collector; a heat transfer assembly coupled to the exhaust air connection; and a fluid system coupled to the heat transfer assembly; an inlet and exhaust transport comprising: an air inlet filter housing coupled to the combustion air connection; and an exhaust stack coupled to the exhaust air connection.

Abstract: Gas analyzer and method for measuring nitrogen oxides in an exhaust gas, wherein to measure the nitrogen oxides, ozone is generated from oxygen, the exhaust gas is treated with the ozone generated to convert nitrogen monoxide within the exhaust gas into nitrogen dioxide, the nitrogen dioxide concentration in the treated exhaust gas is measured photometrically using a first light-emitting diode which emits with a central wavelength between 350 nm and 500 nm and output as the nitrogen oxide concentration in the exhaust gas, and the ozone concentration in the treated exhaust gas is measured photometrically using a second light-emitting diode which emits with a central wavelength between 250 nm and 265 nm, where generation of the ozone using the measured ozone concentration as an actual value is regulated to a prespecified setpoint value to enable reliable continuous measurement of nitrogen oxides in exhaust gases with a low outlay on equipment.

Abstract: A method of detecting nitrogen compound emissions in exhaust gases treated with selective catalytic reduction achieved by injecting a reducing agent into the gases and by passing these gases through a catalyst include sending the signal collected by a gas detector arranged in the exhaust gas downstream from the catalyst and representative of the amount of NOx (NOxsonde) at the catalyst outlet to a computing unit, decomposing this signal into a value representative of the effective NOx amount (NOxréel) at the outlet of catalyst established by the SCR catalyst model, into a detector perturbation coefficient (k) and into a value representative of the ammonia amount (NH3réel) via an integrated model so as to obtain NOxsonde=NOxréel+k.NH3réel, evaluating coefficient (k) from this decomposition, and determining the presence of nitrogen compounds downstream from the catalyst when coefficient (k) is greater than or equal to 1.

Abstract: A method of detecting nitrogen compound emissions in exhaust gases treated with selective catalytic reduction achieved by injecting a reducing agent into the gases and by passing these gases through a catalyst include sending the signal collected by a gas detector arranged in the exhaust gas downstream from the catalyst and representative of the amount of NOx (NOxsonde) at the catalyst outlet to a computing unit, decomposing this signal into a value representative of the effective NOx amount (NOxréel) at the outlet of catalyst established by the SCR catalyst model, into a detector perturbation coefficient (k) and into a value representative of the ammonia amount (NH3réel) via an integrated model so as to obtain NOxsonde=NOxréel+k.NH3réel, evaluating coefficient (k) from this decomposition, and determining the presence of nitrogen compounds downstream from the catalyst when coefficient (k) is greater than or equal to 1.

Abstract: A compound represented by the general formula (I) [R1 and R2 are amino groups that substitute at adjacent positions on the benzene ring; R3 and R4 are halogen atoms; R5 and R6 represent hydrogen atom, an acyl group or an acyloxy(C1-6 alkyl) group; R7 and R8 represent —(CH2)p—N(R9)(R10) (p is 1 to 4, and R9 and R10 represent —(CH2)n—COOH (n is 1 to 4))], which is useful for measuring a reactive nitrogen species existing in cells such as nitrogen monoxide or peroxynitrite at high sensitivity over a long period of time.

Abstract: A method for determining an NOx concentration in a measurement gas is provided, where a measurement value for the NOx concentration is determined from the sensor signal of a gas sensor and a measurement value for the concentration of a second component in the measurement gas is determined. A corrected value for the NOx in the measurement gas is determined from the measurement values, and the measurement value and the corrected measurement value for the NOx concentration are displayed and/or output.

Abstract: A method and device for detecting explosive compounds in an air sample in which the air sample is filtered with activated carbon treated with a weakly basic solution, after which the air sample is divided into two parts, with one part being heated at lower temperatures to decompose non-explosive nitrogenous compounds and the second part being heated at higher temperatures to decompose explosive nitrogenous compounds. Nitrogen dioxide is measured in both portions of the air sample with a spectrographic detector, and the presence or absence of explosive nitrogenous compounds in the air sample is determined.

Abstract: A handheld, small but accurate and reliable device for diagnostic NO measurements using a NO sensor, where the parameters governing the taking of the sample are different from the parameters optimal for the accuracy of said NO sensor. By temporarily storing a portion of the exhaled air, and feeding this to the sensor at a flow rate adapted to the NO sensor, the accuracy and sensitivity of a system/method involving NO sensors, in particular electrochemical NO sensors, can be increased. The method for diagnostic NO measurements comprises steps for controlling the inhalation of NO free air, as well as the exhalation, both by built-in means and by audible and/or visual feedback to the patient.

Abstract: A control system of a NOx removal device is provided with reagent introducing means for introducing a reagent into a fluid, a temperature measuring device that measures a temperature distribution of the fluid, a reagent-concentration calculating portion that calculates a concentration distribution of the reagent introduced into the fluid with the temperature distribution determined at the temperature measuring device, a reagent-flow-rate determining portion that determines a flow rate of the reagent that the reagent introducing means introduces in accordance with the concentration distribution calculated at the reagent-concentration calculating portion, and a reagent-introducing-means control portion that controls the reagent introducing means so as to introduce the reagent into the fluid at the flow rate determined at the reagent-flow-rate determining portion.

Abstract: A gas sensor cell using a liquid crystal composite material is provided. The gas sensor cell has recovery capability and can be reused. Upon gas adsorption, the liquid crystal composite material has visually detectable color changes and changes in electrical properties to facilitate the measurement of gas concentration from low to high.

Abstract: Methods and kits to detect and quantitate NOx compounds in a biological sample are provided. The methods include reacting a mixture that includes a nitrite compound and a chromogenic reagent to form a colored compound, contacting the mixture with a retention medium configured to retain the colored compound, and detecting the colored compound retained on the retention medium.

Abstract: A nitrogen dioxide sensor comprising a first beam having a first functionalized sensing surface capable of sensing nitrogen dioxide, the first beam capable of producing a first resonant frequency; and a second beam having a second functionalized reference surface not capable of sensing nitrogen dioxide, the second beam capable of producing a second resonant frequency, wherein differential sensing of nitrogen dioxide may be performed, further wherein the first beam and the second beam are each functionalized with one or more soft bases having comparable viscoelastic properties is provided. In one embodiment, the sensor is a nano-sensor capable of low drift and accurate detection of nitrogen dioxide levels at the zeptogram level. Methods of making and using a nitrogen dioxide sensor are also provided.

Abstract: The invention relates to the use of carbon nanomaterials as a filtration material pervious to nitrogen dioxide and impervious to ozone. The invention also relates to the use of carbon nanomaterials having a specific surface, measured by the BET method, of 15 to 40 m2/g inclusive and a form factor, equal to the ratio (highest dimension/lowest dimension) of the nanomaterial, of 5 to 250 inclusive, as material for filtering a gas mixture containing nitrogen dioxide and ozone, being pervious to the nitrogen dioxide and impervious to the ozone. The invention can be used in the field of air pollution.

Abstract: The nitrogen oxide analyzer obtains the ozone concentration-luminescence response characteristics that show the relationship between the ozone concentration and the light intensity by chemiluminescent response obtained by varying the ozone concentration alone in a steady state, and sets the relationship of the parameter that determines an average period of the sample gas passing the reactor so that the luminescence response is generated in the reactor alone even though the ozone concentration of the ozone-containing gas changes within a predetermined range based on the ozone concentration-luminescence response characteristics.

Abstract: The present invention provides a device for the detection of a peroxide-based explosive, in particular, triacetone triperoxide (TATP), which is based on a molecular controlled semiconductor resistor (MOCSER) and composed of at least one insulating or semi-insulating layer, at least one conducting semiconductor layer, two conducting pads and a layer of multifunctional organic molecules capable of adsorbing molecules of the peroxide-based explosive. The invention further provides an array of semiconductor devices for the selective detection of a peroxide-based explosive, as well as a method for the selective detection of vapors of a peroxide-based explosive in a gaseous mixture using this array.

Abstract: The present invention provides a means of greatly reducing or eliminating the interferences of UV-absorbing compounds, mercury, water vapor and particulates in the UV absorbance measurement of ozone by replacing the internal solid-phase ozone scrubber with a gas-phase scrubber. Reagent gases well suited as a gas-phase scrubber of ozone include nitric oxide and bromine atoms. Nitric oxide may be supplied by a gas cylinder or by photolysis of either N2O or NO2, both in the absence of oxygen. Bromine atoms are conveniently generated by photolysis of Br2 supplied by a permeation tube. Bromine atoms have the advantage of having a faster reaction with ozone than NO and of being catalytic in their reaction. Nitric oxide has the advantage of being generally less reactive with other components of air.

Abstract: Disclosed herein is a method and apparatus for reducing a nitrogen oxide, and the control thereof.

Abstract: Various systems, devices, NO2 absorbents, NO2 scavengers and NO2 recuperator for generating nitric oxide are disclosed herein. According to one embodiment, an apparatus for converting nitrogen dioxide to nitric oxide can include a receptacle including an inlet, an outlet, a surface-active material coated with an aqueous solution of ascorbic acid and an absorbent wherein the inlet is configured to receive a gas flow and fluidly communicate the gas flow to the outlet through the surface-active material and the absorbent such that nitrogen dioxide in the gas flow is converted to nitric oxide.

Abstract: A method of measuring oxygen-containing nitrogen components including nitrogen dioxide in exhaust gases of internal combustion engines, wherein an exhaust gas sample is taken from a removal point 10 at the exhaust gas pipe 1 and is guided to at least one measuring instrument by means of a removal line, wherein, for the purpose of measuring the oxygen-containing nitrogen components, there are provided a separate removal point 10 and a removal line 11 and that the exhaust gas sample for measuring the oxygen-containing nitrogen components is set to a temperature at which a reaction between the nitrogen dioxide and soot is low.

Abstract: The present invention relates to the field of detection of components in gas phase, and in particular to detection of nitric oxide exhaled as a component of breath, using a liquid crystal assay format and a device utilizing liquid crystals as part of a reporting system.

Abstract: The invention concerns a reagent system for the so-called on-board control of analytical elements, in particular test strips, containing an organic N-oxide or a nitroso compound. The invention also concerns analytical elements containing a reagent system for a detection reaction and a reagent system for an on-board control. Furthermore, the invention concerns a method for checking analytical elements in which a reagent system for an on-board control is examined optically or electrochemically with the aid of a measuring instrument for changes which could indicate a stress of the analytical element.

Abstract: A method for determining the number of drops metered with a drop frequency into a reactor, especially in a high temperature decomposition system for analyzers, wherein a gas stream is flowing through the reactor. There exists in the reactor a temperature, which is greater than the boiling temperature of the liquid, and a drop metered into the reactor transforms at least partially into the gas phase following entry into the reactor, especially due to heat transfer from contact with a surface within the reactor, especially directly after contact with the surface within the reactor. With a sampling rate, which is greater than the drop frequency, a sequence of pressure signals dependent on pressure within the reactor is registered, and, from the sequence of pressure signals or from values derived therefrom, the number of drops metered into the reactor is ascertained.

Abstract: The invention concerns a reagent system for the so-called on-board control of analytical elements, in particular test strips, containing an organic N-oxide or a nitroso compound. The invention also concerns analytical elements containing a reagent system for a detection reaction and a reagent system for an on-board control. Furthermore, the invention concerns a method for checking analytical elements in which a reagent system for an on-board control is examined optically or electrochemically with the aid of a measuring instrument for changes which could indicate a stress of the analytical element.

Abstract: Data on a secular change of each denitration catalyst is managed based on data obtained by a periodic maintenance and a daily management. Management of a secular change and prediction on performance variations that occur until a next periodic check is performed. It is determined whether the denitration catalyst is deteriorated such that an exhaust-gas denitration system cannot maintain its performance. When the denitration catalyst is deteriorated, regeneration, replacement, or addition of the denitration catalyst is performed, and the denitration catalyst is altered as necessary. When the denitration catalyst is usable, the denitration catalyst is not replaced nor regenerated.

Abstract: An apparatus for monitoring ammonia in gaseous streams, particularly in flue gas streams. The apparatus is transportable but can be permanently installed. The flue gas can be monitored in real time.

Abstract: The present invention provides a method of testing an NOx removal catalyst, which method enables assessment of actual catalytic performance in consideration of gas flow condition in the gas conduits of the NOx removal catalyst.

Abstract: Localized catalyst activity in an SCR unit for controlling emissions from a boiler, power plant, or any facility that generates NOx-containing flue gases is monitored by one or more modules that operate on-line without disrupting the normal operation of the facility. Each module is positioned over a designated lateral area of one of the catalyst beds in the SCR unit, and supplies ammonia, urea, or other suitable reductant to the catalyst in the designated area at a rate that produces an excess of the reductant over NOx on a molar basis through the designated area. Sampling probes upstream and downstream of the designated area draw samples of the gas stream for NOx analysis, and the catalyst activity is determined from the difference in NOx levels between the two probes.

Abstract: Highly sensitive devices for detecting nitric oxide and/or other gaseous analytes in gaseous samples are improved by the incorporation of a carbon monoxide scavenger in the interior of the device or in the device packaging. The release of carbon monoxide within the housing of the device by the plastic used in the construction of the housing or by anything within the device that releases carbon monoxide causes a loss in sensitivity due to competition between the carbon monoxide and the nitric oxide for the binding sites on the device sensor. The scavenger corrects this by either catalyzing the oxidation of carbon monoxide to the less competitive carbon dioxide or immobilizing the carbon monoxide by affinity-type or covalent binding. Analogous effects are achieved for analytes other than nitric oxide but that likewise encounter interference from carbon monoxide in binding to sensors.

Abstract: Disclosed herein is a method and apparatus for reducing a nitrogen oxide, and the control thereof.

Abstract: A photochemical sensing system enables the measurement of nitrogen oxides (nitrogen dioxide and nitric oxide) by photolyzing nitrogen dioxide to form oxygen atoms which combine with oxygen molecules to form ozone. Ozone reacts with nitric oxide to for nitrogen dioxide-decreasing ozone. Changes in ozone concentration are measured as a surrogate for the nitrogen dioxide and nitric oxide. Any species which photolyzes to yield oxygen atoms may be measured by this technique. Additional specificity for nitrogen oxides is conferred by allowing the nitric oxide to react with the ozone to recreate the nitrogen dioxide. By periodically photolyzing the nitrogen dioxide (to form ozone), and then allowing the resulting nitric oxide to react with the ozone (thereby reducing ozone), a pulsed signal is obtained whose amplitude is proportional to the total amount of nitrogen dioxide and nitric oxide present. Medical applications include measuring nitric oxide concentrations in expired air samples.

Abstract: A mixed potential sensor device and methods for measuring total ammonia (NH3) concentration in a gas is provided. The gas is first partitioned into two streams directed into two sensing chambers. Each gas stream is conditioned by a specific catalyst system. In one chamber, in some instances at a temperature of at least about 600° C., the gas is treated such that almost all of the ammonia is converted to NOx, and a steady state equilibrium concentration of NO to NO2 is established. In the second chamber, the gas is treated with a catalyst at a lower temperature, preferably less than 450° C. such that most of the ammonia is converted to nitrogen (N2) and steam (H2O). Each gas is passed over a sensing electrode in a mixed potential sensor system that is sensitive to NOx. The difference in the readings of the two gas sensors can provide a measurement of total NH3 concentration in the exhaust gas. The catalyst system also functions to oxidize any unburned hydrocarbons such as CH4, CO, etc.

Abstract: An analytical system is provided for determining nitrogen monoxide, nitrogen dioxide and ozone concentrations in air samples. An ultraviolet light source 4 is used to alter the equilibrium between nitrogen dioxide and oxygen on the one hand and nitrogen monoxide and ozone on the other. Dynamic measurement of ozone concentration with time while ultraviolet irradiation is pulsed enables each gas concentration to be calculated without requiring input gases to be scrubbed. An aApparatus 101 is further provided to provide a controlled flow of gas to a sensor 103 attached to a high altitude balloon while sheltering it from the elements and allowing for affects of temperature, said apparatus comprising a shield 104 and a gas conducting means which uses the venturi effect to control air flow or has a hole to allow water to drain without affecting air flow past the sensor.

Abstract: A method of determining bias in a measurement of a constituent concentration level in a sample gas is provided. The method comprises establishing a sample gas flow from an emission stream into a sample gas line of an emissions monitoring system. The method further comprises removing water from the sample gas flow and cooling the sample gas flow to a temperature below about 41° F. to produce a cooled, dried sample gas flow. The constituent concentration level is then determined for the cooled, dried sample gas flow. The method further comprises introducing a span gas having a known span gas constituent concentration level into the sample gas flow to form a combined sample and span gas flow, the span gas being introduced at a desired span gas flow rate. The method still further comprises removing water from the combined sample and span gas and cooling the combined sample and span gas to a temperature below about 41° F. to produce a cooled, dried, combined sample and span gas flow.

Abstract: A lightweight and portable analyzer is provided. At least one component of the analyzer is made from a lightweight material, such as ABS. A manifold can have a plate and gas passages ultrasonically welded together. By having at least one component made from a lightweight material, the analyzer is lighter.

Abstract: A system for determining a reagent solution quality indicator includes a reagent solution source for supplying the reagent solution to an emissions catalyst configured to receive a NOx-containing gas therethrough, means for determining a flow rate of NOx reduced from the gas by the catalyst, means for determining a flow rate of the reagent solution into the catalyst, and a control circuit determining the reagent solution quality indicator as a function of the NOx flow rate and the reagent solution flow rate. The system may additionally be configured to diagnose reagent solution quality by configuring the control circuit to monitor the reagent solution quality indicator over time and produce a fault value if the reagent solution quality indicator crosses a reagent quality indicator threshold, and to diagnose the catalyst by producing another fault value if the catalyst capacity point falls outside of a catalyst capacity point threshold.

Abstract: The present invention relates to an apparatus and method for determining the concentration of nitric oxide (NO) in a gas mixture such as air. The gas sample containing NO is mixed with a gas containing ozone (O3), and the change in the ozone concentration is measured after a sufficient time is allowed for the reaction between NO and O3 to take place and destroy a measurable quantity of O3. In the disclosed embodiment, the concentration of ozone is measured using the technique of UV absorption. In this case, the invention has the advantage over other instruments for measuring NO of having absolute calibration based on the known extinction coefficient for ozone at ultraviolet wavelengths. The invention discloses both static and dynamic flow systems, and the NO concentration measurements may be made over a wide pressure range.

Abstract: A method and system for determining a concentration level of NOx in an exhaust stream from a combustion source. The method comprises capturing sample gas from the exhaust stream using a sampling device. NO2 in the sample gas is converted to NO by passing the sample gas through a catalytic NO2 converter. The method also comprises removing water from the sample gas by passing the sample gas through a dryer and determining a sample gas NO concentration level. The step of converting NO2 is performed at a temperature above the dew point temperature of the sample gas.

Abstract: A diagnostic system for monitoring catalyst performance in an exhaust system comprises a plurality of treatment devices catalytically treating an exhaust gas stream, and a plurality of gas sensors for monitoring the catalyst performance of the treatment devices to determine when sulfur poisoning occurs. An on-board diagnostic system receives signals from the gas sensors, and, based upon response time differentials between sensors, determines whether the treatment devices are experiencing sulfur poisoning.

Abstract: The present invention provides a NOx-concentration measuring apparatus D for quantitatively analyzing the concentration of NOx contained in a sample gas. The measuring apparatus D comprises a sampling probe for obtaining the sample gas, a drain separator 2 for condensing moisture contained in the sample gas as a condensed water and separating the condensed water from the sample gas, an NO2 converter 3 for converting NO2 contained in the sample gas into NO, a secondary cooling device 7 for additionally cooling the sample gas, and an NO analyzer 1, arranged in this order with respect to a sample-gas line of the NOx-concentration measuring apparatus. The drain separator is a high-flow-velocity cooling type drain separator. Further, the sample-gas line between the sampling probe and the drain separator is heated and/or thermally insulated over the entire length thereof. The measuring apparatus can provide a high-precision measurement while suppressing NO2 loss.

Abstract: Methods and apparatus are described for preventing nitrogen interference in the detection of a substance. In particular, it relates to new methods and apparatus for preventing interference due to nitrogen in pyro-electrochemical methods for measuring substances, for example sulfur content, contained within liquids such as petroleum products and beverages. One preferred apparatus and method comprises a catalytic converter or thermal converter to selectively remove the nitrogen-containing interferant, for example NO2, in the pyrolyzed gas stream to NO without affecting the sulfur content. A second preferred apparatus and method comprises a chemical scrubber to selectively remove the nitrogen-containing interferant from the gas stream without affecting the sulfur content.

Abstract: It is discovered that a composition comprising at least one amine and at least one stabilizer may be useful in detecting the presence of an adulterant in a urine sample. Such adulterant includes an oxidizing agent.

Abstract: A diagnostic system for monitoring catalyst performance in an exhaust system comprises a plurality of treatment devices catalytically treating an exhaust gas stream, and a plurality of gas sensors for monitoring the catalyst performance of the treatment devices to determine when sulfur poisoning occurs. An on-board diagnostic system receives signals from the gas sensors, and, based upon response time differentials between sensors, determines whether the treatment devices are experiencing sulfur poisoning.

Abstract: A method and apparatus for measuring the concentration of at least one gaseous component and/or vaporous component of a gaseous mixture in which a controlled sensor flame is introduced into the gaseous mixture and at least one narrow spectral band in the controlled sensor flame is optically measured. The concentration of the gaseous component using a result obtained from the optical measuring of the at least one narrow spectral band is then calculated. The method of this invention is particularly suitable for substantially real-time control of combustion processes.

Abstract: A compound represented by the, following formula (I) or (II): 1

Abstract: An optical gas sensor for determining a gas, in particular in air, having a radiation source, a detector and a sensitive layer in the beam path of the radiation source. The sensitive layer contains at least one oligomer or polymer having at least one side chain, the side chain having at least one basic or acidic functional group.

Abstract: The concentration of nitric oxide in a gas is determined by oxidizing NO to NO2 and then measuring the concentration of NO2 in the gas, which is proportional to the concentration of NO. Preferably, gaseous NO2 molecules diffuse through a plurality of capillary membrane fibers and undergo a chemiluminescent reaction with a reagent flowing within; the light from the reaction is measured to determine NO2 concentration. In another aspect of a preferred embodiment, gas is passed through a scrubber before the concentration of NO2 is measured, in order to substantially remove carbon dioxide and ambient NO2 from the gas without substantially affecting the concentration of nitric oxide therein.

Abstract: An analyzer compensates for gas flow perturbations by providing a makeup flow of carrier gas to maintain the pressure and/or flow rate of analyte and inert gas through a detector constant such that a accurate determination of a low concentration of an analyte in the presence of a high concentration of a second analyte can be accurately determined. In one embodiment, a carrier gas is introduced through a valve responsive to the detected pressure in the gas flow stream between a scrubber and a subsequent detector for maintaining the pressure constant during an analysis. In another embodiment of the invention, a flow transducer is positioned in the gas flow path between the scrubber and detector and coupled to a flow control valve coupled to introduce carrier gas as a function of detected gas flow such that the flow rate of gas into the detector is maintained constant.

Abstract: There is provided a semiconductor device in which substantially no deformation of a bonded wire occurs, and a method for producing the semiconductor device. A wiring pattern of a wiring substrate and an electrode of an IC chip are connected by a wire. A contact prevention resin whose height is higher than the highest position of the bonded wire, is adhered to the approximate center of the surface of the IC chip. If the wiring substrate warps due to heat from the lower metallic mold, an inner surface of an upper metallic mold placed on the wiring substrate abuts against the contact prevention resin, and decrease warpage of the wiring substrate. Accordingly, the wire is kept from contacting the inner surface of the upper metallic mold. Thereafter, the IC chips, the wires, and the like are sealed by injecting a mold resin into the molds.

Abstract: A method and system for determining a concentration level of NOx in an exhaust stream from a combustion source. The method comprises capturing sample gas from the exhaust stream using a sampling device. NO2 in the sample gas is converted to NO by passing the sample gas through a catalytic NO2 converter. The method also comprises removing water from the sample gas by passing the sample gas through a dryer and determining a sample gas NO concentration level. The step of converting NO2 is performed at a temperature above the dew point temperature of the sample gas.

Abstract: A method and system for determining a concentration level of NOx in an exhaust stream from a combustion source. The method comprises capturing sample gas from the exhaust stream using a sampling device. NO2 in the sample gas is converted to NO by passing the sample gas through a catalytic NO2 converter. The method also comprises removing water from the sample gas by passing the sample gas through a dryer and determining a sample gas NO concentration level. The step of converting NO2 is performed at a temperature above the dew point temperature of the sample gas.